Vessel Motion During Side-By-Side Offloading: Comparison of Field Data and Numerical Model

The side-by-side (SBS) offloading operation is a conventional industry practice when an FLNG facility offloads liquid cargo onto carriers. There are several criteria for this operation to ensure safety and operability. Carrier motion during the SBS offloading has been studied extensively by either computational models or laboratory scaled models. Comparison between these results and full-scale measurements of vessel motions that are recorded during actual offloads has also been studied by JIPs and companies, but almost none of this is presently available in the public literature. This paper presents, for the first time, a vessel motion comparison between numerical model and field measurements. In particular, aspects which are challenging to model numerically, and therefore interesting to investigate in the comparison include roll motion, motions coupled to gap resonance, and motions coupled to sloshing.